Many types of rotatable structures, such as motors, gimbal joints, hinges, and the like have a rotating shaft. In some instances, it has been desirable to measure the angular position of the shaft at various times during its operation. A gimbal is one type of rotatable structure that provides for rotation of an object in three dimensions. Objects such as cameras or other visual aid devices have been implemented on gimbals to enable rotation of the camera's eyepiece to virtually any geometrical orientation. One such type of visual aid device is an electro optical/infrared (EO/IR) sensor. The electro optical/infrared sensor is a type of camera that is capable of taking pictures using both the visible and infrared portions of the electromagnetic spectrum. When mounted onto a gimbal, the electro optical/infrared sensor is capable of deriving images from virtually any orientation.